/*
 ======================================================================
 RSS JavaScript Ticker object
 Author: George at JavaScriptKit.com / DynamicDrive.com
 Created: Feb 5th, 2006
 Updated: Jul 24th, 2008 (USAgNet)
 ======================================================================
*/

function createAjaxObj(){
     var httprequest = false
     if(window.XMLHttpRequest){ // if Mozilla, Safari etc
          httprequest = new XMLHttpRequest()
          if(httprequest.overrideMimeType)
               httprequest.overrideMimeType('text/xml')
          }
     else if(window.ActiveXObject){ // if IE
          try{
               httprequest = new ActiveXObject("Msxml2.XMLHTTP");
          } 
          catch(e){
               try{
                    httprequest = new ActiveXObject("Microsoft.XMLHTTP");
               }
               catch (e){}
          }
     }
     return httprequest
}

// -------------------------------------------------------------------
// Main RSS Ticker Object function
// rss_ticker(RSS_id, cachetime, divId, divClass, delay, optionalswitch)
// -------------------------------------------------------------------

function rss_ticker(RSS_id, cachetime, divId, divClass, delay, optionalswitch){
     this.RSS_id=RSS_id //Array key indicating which RSS feed to display
     this.cachetime=cachetime //Time to cache feed, in minutes. 0=no cache.
     this.tickerid=divId //ID of ticker div to display information
     this.delay=delay //Delay between msg change, in miliseconds.
     this.logicswitch=(typeof optionalswitch!="undefined")? optionalswitch : -1
     this.mouseoverBol=0 //Boolean to indicate whether mouse is currently over ticker (and pause it if it is)
     this.pointer=0
     this.ajaxobj=createAjaxObj()
     document.write('<div id="'+divId+'" class="'+divClass+'">Initializing ticker...</div>')
     this.getAjaxcontent()
}

// -------------------------------------------------------------------
// getAjaxcontent()- Makes asynchronous GET request to "rssfetch.php" with the supplied parameters
// -------------------------------------------------------------------

rss_ticker.prototype.getAjaxcontent = function(){
     if(this.ajaxobj){
          var instanceOfTicker = this
          var parameters = "id="+encodeURIComponent(this.RSS_id)+"&cachetime="+this.cachetime+"&bustcache="+new Date().getTime()
          this.ajaxobj.onreadystatechange = function(){instanceOfTicker.initialize()}
          this.ajaxobj.open('GET', "rss_ticker/rss_fetch.php?"+parameters, true)
          this.ajaxobj.send(null)
     }
}

// -------------------------------------------------------------------
// initialize()- Initialize ticker method.
// -Gets contents of RSS content and parse it using JavaScript DOM methods 
// -------------------------------------------------------------------

rss_ticker.prototype.initialize = function(){ 
     if(this.ajaxobj.readyState == 4){ //if request of file completed
          if(this.ajaxobj.status == 200){ //if request was successful
               var xmldata = this.ajaxobj.responseXML
               if(xmldata.getElementsByTagName("item").length == 0){ //if no <item> elements found in returned content
                    document.getElementById(this.tickerid).innerHTML = "<b>Error:</b> unable to fetch RSS feed!<br />"+this.ajaxobj.responseText
                    return
               }
               var instanceOfTicker = this
               this.feeditems = xmldata.getElementsByTagName("item")

               //Cycle through RSS XML object and store each peice of the item element as an attribute of the element
               for (var i = 0; i < this.feeditems.length; i++){
                    this.feeditems[i].setAttribute("ctitle", this.feeditems[i].getElementsByTagName("title")[0].firstChild.nodeValue)
                    this.feeditems[i].setAttribute("clink", this.feeditems[i].getElementsByTagName("link")[0].firstChild.nodeValue)
                    this.feeditems[i].setAttribute("cdescription", this.feeditems[i].getElementsByTagName("description")[0].firstChild.nodeValue)
               }
               document.getElementById(this.tickerid).onmouseover = function(){instanceOfTicker.mouseoverBol=1}
               document.getElementById(this.tickerid).onmouseout = function(){instanceOfTicker.mouseoverBol=0}
               this.rotatemsg()
          }
     }
}

// -------------------------------------------------------------------
// rotatemsg()- Rotate through RSS messages and displays them
// -------------------------------------------------------------------

rss_ticker.prototype.rotatemsg = function(){
     var instanceOfTicker = this
     if(this.mouseoverBol == 1) //if mouse is currently over ticker, do nothing (pause it)
          setTimeout(function(){instanceOfTicker.rotatemsg()}, 100)
     else{
          var tickerDiv = document.getElementById(this.tickerid)
          var tickercontent = '<a href="'+this.feeditems[this.pointer].getAttribute("clink")+'" target="_blank">'+this.feeditems[this.pointer].getAttribute("ctitle")+'</a>'
          if(this.logicswitch == "showdescription")
               tickercontent += "<br />"+this.feeditems[this.pointer].getAttribute("cdescription")
          tickerDiv.innerHTML = tickercontent
          this.pointer = (this.pointer<this.feeditems.length-1) ? this.pointer + 1 : 0
          setTimeout(function(){instanceOfTicker.rotatemsg()}, this.delay) //update container every second
     }
}